CN203828932U - Permanent magnet for nuclear magnetic resonance imager - Google Patents
Permanent magnet for nuclear magnetic resonance imager Download PDFInfo
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- CN203828932U CN203828932U CN201420132378.2U CN201420132378U CN203828932U CN 203828932 U CN203828932 U CN 203828932U CN 201420132378 U CN201420132378 U CN 201420132378U CN 203828932 U CN203828932 U CN 203828932U
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- permanent magnet
- magnet
- polygon
- magnetic resonance
- nuclear magnetic
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- 238000005481 NMR spectroscopy Methods 0.000 title abstract description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 31
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 29
- 239000010959 steel Substances 0.000 claims abstract description 29
- 229910052742 iron Inorganic materials 0.000 claims abstract description 11
- 229910001172 neodymium magnet Inorganic materials 0.000 claims abstract description 9
- 229910000808 amorphous metal alloy Inorganic materials 0.000 claims abstract description 8
- 230000015572 biosynthetic process Effects 0.000 claims abstract 3
- 238000013421 nuclear magnetic resonance imaging Methods 0.000 claims description 18
- 230000005389 magnetism Effects 0.000 claims description 11
- 238000003384 imaging method Methods 0.000 claims description 10
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 9
- 150000002910 rare earth metals Chemical class 0.000 claims description 9
- 238000003475 lamination Methods 0.000 claims description 8
- 239000000696 magnetic material Substances 0.000 claims description 8
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 238000009413 insulation Methods 0.000 claims description 5
- 229910001208 Crucible steel Inorganic materials 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims description 3
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 abstract 1
- 239000011438 cord wood Substances 0.000 abstract 1
- 239000000463 material Substances 0.000 description 6
- 229910052802 copper Inorganic materials 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 239000000956 alloy Substances 0.000 description 3
- 230000005415 magnetization Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910002520 CoCu Inorganic materials 0.000 description 2
- 229910052692 Dysprosium Inorganic materials 0.000 description 2
- 229910000976 Electrical steel Inorganic materials 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910017518 Cu Zn Inorganic materials 0.000 description 1
- 229910017752 Cu-Zn Inorganic materials 0.000 description 1
- 229910017943 Cu—Zn Inorganic materials 0.000 description 1
- 101000993059 Homo sapiens Hereditary hemochromatosis protein Proteins 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- 206010067482 No adverse event Diseases 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002146 bilateral effect Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- TVZPLCNGKSPOJA-UHFFFAOYSA-N copper zinc Chemical compound [Cu].[Zn] TVZPLCNGKSPOJA-UHFFFAOYSA-N 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000009931 harmful effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000005865 ionizing radiation Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000005300 metallic glass Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000004451 qualitative analysis Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
The utility model discloses a permanent magnet for a nuclear magnetic resonance imager. The permanent magnet comprises upper and lower rack covers and double pillars, wherein the upper and lower rack covers and the pillars are connected through bolts to form a cordwood assembled H-shaped yoke iron; magnetic steels, electrode plates, field uniforming rings, vortex plates, gradient coils and transmitting coils are symmetrically mounted on the upper and lower rack covers in sequence so as to form a testing area; the field uniforming rings are mounted at the outer end parts of the electrode plates; the vortex plates are mounted in the field uniforming rings; the gradient coils and the transmitting coils are mounted on the vortex plates in the field uniforming rings; the magnetic density of the permanent magnet image formation area (namely the ball area, of which the diameter is 400 mm, in the central area of the permanent magnet) is 4000 gauss to 5500 gauss. The vortex plates bonded by iron-based amorphous alloy soft magnetic strip 1K101 amorphous sheets can better eliminate or reduce vortex generated by the electrode plates, the signal-to-noise ratio is better, and the image formation is clearer; through the adoption of the N52-N55 high-performance neodymium iron boron gradient-transmitting integrated coil, the overall size of the permanent magnet is reduced, the weight of the complete machine is reduced, the processing is simple, the structure is various, and field uniforming is facilitated.
Description
Technical field
This utility model belongs to nuclear magnetic resonance, NMR field, particularly relates to a kind of permanent magnet for nuclear magnetic resonance imaging instrument.
Background technology
Nd-Fe-B rare earth permanent magnetic material, is more and more applied with its good magnetic property, is widely used in medical nuclear magnetic resonance imaging instrument field.Nuclear magnetic resonance imaging instrument, not only in medical field extensive use, looks for well also to have potential application widely in Food Science, mine locating.
As the staple product of medical device industry, medical diagnosis image instrument is one of requisite equipment of situation of all-level hospitals.Wherein, quantity of information that nuclear magnetic resonance imaging instrument provides is maximum, without ionizing radiation, and human body is had no adverse effects.Compare with CT with X ray, it is high that nuclear magnetic resonance has resolution, and imaging parameters is many, and diagnostic area is wide, can arbitrary cross-section scanning, noinvasive harmless, without advantages such as radiation hazards, become one of mainstream development direction of medical image diagnostic apparatus.Permanent magnet in nuclear magnetic resonance imaging instrument is core component, to reducing noise, improves image quality and plays decisive role.
Patent of invention CN94114872.6 provides < < high uniformity vortex-free plate type NMR imaging instrument to provide the two column open C-type permanent-magnet magnetic resonance magnet > > of < < with permanent-magnet > > and utility model patent CN2542205Y, and the structure of permanent-magnet is described in detail; Patent of invention CN1401295A and utility model patent CN2493161Y provide the permanent magnet > > of < < for nuclear magnetic resonance imaging instrument, have proposed to adopt cross current compensator to eliminate the eddy current effect producing due to high-power gradient current and the harmful effect that picture quality is brought.But there is defect or deficiency in the ability that improves the magnetic field intensity of permanent magnet, reduction noise, raising image quality, minimizing total quality, raising processing assembly and adjustment efficiency and reduction permanent magnet cost in prior art.
Summary of the invention
In order to solve prior art, improving the magnetic field intensity of permanent magnet, reduce noise, improving defect or the deficiency of the ability existence of image quality and minimizing total quality, this utility model provides a kind of permanent magnet for nuclear magnetic resonance imaging instrument.
This utility model is achieved through the following technical solutions:
A kind of permanent magnet for nuclear magnetic resonance imaging instrument, comprise upper and lower housing cap and two column, and be bolted and form building block system assembly type H type yoke, on upper and lower housing cap, symmetry is equipped with magnet steel, pole plate, grading ring, eddy-current disc, gradient coil and transmitting coil in order, form imaging area, imaging area is permanent magnet detection zone (being that permanent magnet center zone diameter is the ball territory of 400mm), and magnetic field intensity is 4000 ~ 5500 Gausses; On pole plate, grading ring is equipped with in outer end; Eddy-current disc is housed in grading ring; Gradient coil and transmitting coil are also housed in grading ring.
Upper and lower housing cap and two column adopt steel plate or the ZG200-400 cast steel of No. 10 steel matter.
Magnet steel is the polygon lifting magnet that N52 ~ N55 Nd-Fe-B rare earth permanent magnetic material is made; Pole plate is the polygon ferrum plate that electrical pure iron DT4 makes; Eddy-current disc is insulate the layer by layer polygon soft magnet plate of the bonding in bulk piece insulation of lamination rectangular block of stack of amorphous thin slice that Fe-based amorphous alloy band is made, several this polygon soft magnet plates are the bonding polygon eddy-current disc of making of fissure of displacement insulation again, and wherein lamination direction is perpendicular to magnetic direction; Grading ring is the polygon iron hoop that electrical pure iron DT4 makes.
Described magnet steel is that N52 ~ N55 Nd-Fe-B rare earth permanent magnetic material is made; Described Nd-Fe-B rare earth permanent magnetic material contains Pr, Nd, Co, Cu, wherein Pr/Nd=0.2 ~ 0.4, Co=0.5 ~ 1.5wt%, Cu=0.1 ~ 0.2wt%.
Magnet steel is by the bonding polygon lifting magnet of making of square column piece.
The soft magnet plate that eddy-current disc adopts Fe-based amorphous alloy soft magnetism band 1K101 amorphous thin slice to make to be the bonding piece of making of lamination rectangular block and the piece insulation size by the stack that insulate to be layer by layer less than grading ring inside dimensions, then by a plurality of so bonding one-tenth polygon of soft magnet plate fissure of displacement mutually insulated eddy-current discs.
Gradient coil and transmitting coil are gradient and the integrated coil of transmitting.
Permanent magnet is the two column open frame structures of H type, the horizontal open angle that has increased permanent magnet is avoided the sense of patient's fear of confined spaces, for the two column open frame structures of H type, adopt polygon lifting magnet, need to increase magnetic steel material or adopt N52 ~ N55 magnet steel of high magnetic characteristics to guarantee test section magnetic field intensity.
The beneficial effect that this utility model brings is:
Outside the Pass the generation of eddy current and magnetization condition, eddy-current disc physical dimension have, also relevant with the resistivity of eddy-current disc material (being inversely proportional to), the eddy current that pole plate produces can be eliminated or reduce to the eddy-current disc that adopts the high Fe-based amorphous alloy soft magnetism band 1K101 of resistivity of material to make better, signal to noise ratio is more excellent, and imaging is more clear; Amorphous is a kind of novel magnetically soft alloy material, it adopts super chilling technique that motlten metal is directly cooling with the speed of 1,000,000 degree per second, forming thickness is the noncrystal strip of 25--28 μ m, obtain thering is shortrange order in atomic arrangement combination, the non-crystaline amorphous metal tissue of the unordered feature of long-range is different from traditional metal and alloy material completely in microstructure.Fe-based amorphous band has ultramicro crystal kernel structure, with its high pcrmeability, high saturated magnetic strength, low iron loss and good stability, met current electronic product to the needs of high frequency, large electric current, miniaturization, energy-saving future development, can substitute silicon steel and ferrite, be applied in the permanent magnet of nuclear magnetic resonance imaging instrument.
Adopt mainly by Pr/Nd=0.2 ~ 0.4, Pr
25nd
75n52 ~ N55 high-performance Ne-Fe-B that 29 ~ 31wt%, Co 0.9 ~ 1.5wt%, Cu 0.1 ~ 0.3wt% form reduces the use of heavy rare earth dysprosium, thereby has reduced production cost; In magnet steel, CoCu's combines to add and has not only improved corrosion resistance and improve again magnet steel magnetic property.Adopt gradient, launch integrated coil and can realize permanent magnet height dimension and reduce; Be bolted and form building block system assembly type H type yoke, can realize overall mass and alleviate, processing technique is simple, and structure is changeable and be convenient to shimming.
Accompanying drawing explanation
Fig. 1 is H type magnet structure schematic diagram
Fig. 2 is magnet piece and amorphous block structure schematic diagram in polygon magnet steel
In figure: 1, two columns; 2, upper and lower polygon housing cap; 3, polygon magnet steel; 4, polygon pole plate; 5, polygon grading ring; 6, polygon eddy-current disc; 7, integrated coil; 8, imaging area; 9, magnet piece; 10, soft magnetism piece.
The specific embodiment
As shown in Figure 1, this utility model adopts the Open architecture of two columns 1 to form symmetrical bilateral magnetic loop by upper and lower polygon housing cap 2 and two column 1, two columns 1 and upper and lower polygon housing cap 2 are bolted and form building block system assembly type H type yoke, two columns 1 and upper and lower polygon housing cap 2 adopt steel plate or the ZG200-400 cast steel of No. 10 steel matter, and two columns 1 column cross section is rectangle; On upper and lower polygon housing cap 2, symmetry is equipped with polygon magnet steel 3, polygon pole plate 4, polygon grading ring 5, polygon eddy-current disc 6, integrated coil 7 in order, form imaging area 8, imaging area 8 is permanent magnet detection zone (being that permanent magnet center zone diameter is the ball territory of 400mm), and magnetic field intensity is 4000 ~ 5500 Gausses; Polygon pole plate 4 is made by electrical pure iron DT4, and polygon magnet steel 3 is made by the high-performance Ne-Fe-B magnet steel of N52 ~ N55; On polygon pole plate 4, outer end is provided with the polygon grading ring 5 that electrical pure iron DT4 makes, in polygon grading ring 5, be provided with the polygon eddy-current disc 6 that soft magnet base noncrystal alloy 1K101 band is made, eddy current situation: X, Y-direction <0.4%, Z direction <1.0%@100Gs/m; On the epoxy plate of polygonal amorphous eddy-current disc 15, paste magnetic sheet shimming, the uniformity: during Φ 500mm * 380mm ball, the uniformity: 80ppm; During Φ 400mm * 350mm ball, the uniformity: 20ppm; In polygon grading ring 5, be provided with gradient and the integrated coil 7 of transmitting.
As shown in Figure 2, polygon magnet steel 3 is N52 ~ N55 Nd-Fe-B rare earth permanent magnetic material, is by the bonding polygon lifting magnet of making of square post magnet piece 9.It is the bonding soft magnet plate that is less than grading ring inside dimensions of making of rectangle soft magnetism piece 10 by the stack that insulate layer by layer that polygon eddy-current disc 6 adopts Fe-based amorphous alloy soft magnetism band 1K101 material, by a plurality of so bonding one-tenth polygon of soft magnet plate fissure of displacement mutually insulated eddy-current discs, wherein lamination direction is perpendicular to magnetic direction again.Wherein soft magnetism piece 10 is that stack is bonding forms by hundreds of layer amorphous thin slice (only 25-28 μ m are thick), because being become by epoxy bond between every layer of amorphous sheet, so insulate layer by layer.
The qualitative analysis formula that under characteristic frequency, eddy current produces: i=4K*f*Bm*h*a
2/ 8 ρ; Wherein: i is eddy current, K is form-factor, and f is magnetization frequency, and Bm is magnetic induction peak value, the thickness that h is pole plate, and the resistivity that ρ is plate material, a is the pole plate length of side.By above formula, can be obtained, outside the Pass the generation of eddy current and magnetization condition, eddy-current disc amorphous lamination piece physical dimension have, also relevant with the resistivity of eddy-current disc material (being inversely proportional to).ρ=40 ~ 50 μ Ω the .cm of stalloy adds 4% chromium ρ=82 μ Ω .cm in 4.5% silicon steel.Ferritic ρ=102 ~ 104 of Cu-Zn, Ni-Zn Ω .m, 1K101 amorphous thin ribbon ρ=130 μ Ω .cm.The eddy-current disc that adopts stalloy to make, eddy current situation: X, Y-direction <1.0%, Z direction <2.5%@100Gs/m; The eddy-current disc that adopts Fe-based amorphous alloy soft magnetism band 1K101 amorphous thin slice to make, eddy current situation: X, Y-direction <0.4%, Z direction <1.0%@100Gs/m.
The Nd-Fe-B rare earth permanent magnetic material of N52 ~ N55 magnet steel mainly comprises Pr/Nd 0.2 ~ 0.4, Pr
25nd
7529 ~ 31wt%, Co 0.9 ~ 1.5wt%, Cu 0.1 ~ 0.3wt%, because of Pr
25nd
75be the composition that nature exists, thereby do not need again the separated production cost that reduced; In magnet steel, have Pr can improve coercivity, Pr adds and reduces the use of heavy rare earth dysprosium, thereby has reduced production cost; The combining to add and not only improved corrosion resistance and improve again magnet steel magnetic property of CoCu in magnet steel, but it is also noted that Co does not have corrosion resistance lower than 0.9wt%, higher than 1.5wt%, can lower remanent magnetism.Add Co to add again Cu can further improve corrosion resistance, but it is also noted that lower than 0.1wt% inoperatively, and can reduce remanent magnetism higher than 0.3wt%.
The open permanent magnet of embodiment 1:H type
Main field strength: 5000 ± 50Gs(magnet constant temperature is in the time of 32 ℃);
Magnetic material: NdFeB;
Remanent magnetism Br:14.9KGs;
Coercivity bHc: >=10.5KOe;
Maximum magnetic energy product (BH) max:53MGOe;
Magnet steel height: 220mm;
Magnetic direction: vertical, upper pole face is S;
Magnet gap: pole-face is to pole-face 510mm;
Plate width: 1400mm;
The uniformity: during Φ 500mm * 380mm ball, the uniformity: 100ppm; During Φ 400mm * 350mm ball, the uniformity: 20ppm;
Eddy current situation: magnet has anti-eddy current and processes (X, Y-direction <0.4%, Z direction <1.0%@100Gs/m)
Magnet outside dimension: wide 1.5 m; High 1.9m; Long 2.8m
Claims (8)
1. for a permanent magnet for nuclear magnetic resonance imaging instrument, comprise upper and lower housing cap and two column, it is characterized in that, described upper and lower housing cap and two column are bolted and form building block system assembly type H type yoke; On described upper and lower housing cap, symmetry is equipped with magnet steel, pole plate, grading ring, eddy-current disc, gradient coil and transmitting coil in order, the formation imaging area, ball territory that is 400mm in permanent magnet center zone diameter; On described pole plate, grading ring is equipped with in outer end; In described grading ring, eddy-current disc is housed; In described grading ring, on eddy-current disc, gradient coil and transmitting coil are also housed.
2. a kind of permanent magnet for nuclear magnetic resonance imaging instrument according to claim 1, is characterized in that: described housing cap up and down and pair column are the steel plate of No. 10 steel matter or are ZG200-400 cast steel.
3. a kind of permanent magnet for nuclear magnetic resonance imaging instrument according to claim 1, it is characterized in that: described eddy-current disc is insulate the layer by layer polygon soft magnet plate of the bonding in bulk piece insulation of lamination rectangular block of stack of amorphous thin slice that Fe-based amorphous alloy band is made, several such polygon soft magnet plates are the bonding eddy-current disc of making of fissure of displacement insulation again, and wherein lamination direction is perpendicular to magnetic direction.
4. a kind of permanent magnet for nuclear magnetic resonance imaging instrument according to claim 1, is characterized in that, described magnet steel is the polygon disk that Nd-Fe-B rare earth permanent magnetic material is made; Described pole plate is the polygon ferrum plate that electrical pure iron DT4 makes; Described grading ring is the polygon iron hoop that electrical pure iron DT4 makes.
5. a kind of permanent magnet for nuclear magnetic resonance imaging instrument according to claim 1, is characterized in that: described magnet steel is by the bonding polygon lifting magnet of making of square column piece.
6. a kind of permanent magnet for nuclear magnetic resonance imaging instrument according to claim 1, it is characterized in that: described eddy-current disc adopts Fe-based amorphous alloy soft magnetism band 1K101 amorphous thin slice to make the bonding soft magnet plate that is less than grading ring inside dimensions of making of lamination rectangular block of the stack that insulate layer by layer, then by a plurality of so bonding one-tenth polygon of soft magnet plate fissure of displacement mutually insulated eddy-current discs.
7. a kind of permanent magnet for nuclear magnetic resonance imaging instrument according to claim 1, is characterized in that: described gradient coil and transmitting coil are gradient and the integrated coil of transmitting.
8. a kind of permanent magnet for nuclear magnetic resonance imaging instrument according to claim 1, is characterized in that: described imaging area is permanent magnet detection zone, and magnetic field intensity is 4000 ~ 5500 Gausses.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420132378.2U CN203828932U (en) | 2014-03-21 | 2014-03-21 | Permanent magnet for nuclear magnetic resonance imager |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420132378.2U CN203828932U (en) | 2014-03-21 | 2014-03-21 | Permanent magnet for nuclear magnetic resonance imager |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203828932U true CN203828932U (en) | 2014-09-17 |
Family
ID=51506832
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420132378.2U Expired - Lifetime CN203828932U (en) | 2014-03-21 | 2014-03-21 | Permanent magnet for nuclear magnetic resonance imager |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103860178A (en) * | 2014-03-21 | 2014-06-18 | 沈阳中北真空磁电科技有限公司 | Permanent magnet used for nuclear magnetic resonance imager |
-
2014
- 2014-03-21 CN CN201420132378.2U patent/CN203828932U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103860178A (en) * | 2014-03-21 | 2014-06-18 | 沈阳中北真空磁电科技有限公司 | Permanent magnet used for nuclear magnetic resonance imager |
| CN103860178B (en) * | 2014-03-21 | 2016-04-06 | 沈阳中北真空磁电科技有限公司 | A kind of permanent magnet for nuclear magnetic resonance imaging instrument |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20200414 Address after: 110168 Liaoning Province, Shenyang Hunnan Huiquan Road No. 8 Patentee after: Shenyang Zhongbei Tongci Technology Co.,Ltd. Address before: 110168 No. 19, main street, offshore economic zone, Liaoning, Shenyang Patentee before: China North Magnetic & Electronic Technology Co.,Ltd. |
|
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20140917 |